At most dances, there's a big grindfest in the middle of the dance floor, where all the girls are back to back in a big circle grinding asses together, while all the guys make a bigger circle around them, jumping up and down and acting like frat guys.

Suzy: Did you go to the dance?
Annie: Yeah.
Suzy: I didn't see you.
Annie: I was in the middle..in the grindfest.
Suzy: Whore.